Dental pulp vascular permeability changes induced by dental bleaching

aiming to compare the effect of different light sources for dental bleaching on vascular permeability of dental pulps, forty-eight incisors were used. the bleaching agent (35 % hydrogen peroxide) was activated by halogen light; led (light emitting diode) or led, followed by laser phototherapy (lpt) (λ = 780 nm; 3 j/cm2). after the bleaching procedures, the animals received an intra-arterial dye injection and one hour later were sacrificed. the teeth were diaphanized and photographed. the amount of blue stain content of each dental pulp was quantified using a computer imaging program. the data was statistically compared (p < 0.05). the results showed a significant higher (p < 0.01) dye content in the groups bleached with halogen light, compared with the control, led and led plus lpt groups. thus, tooth bleaching activated by led or led plus lpt induces lesser resulted in increased vascular permeability than halogen light.